But as wife Kate Middleton enters the final stages of her pregnancy it seems the nerves are kicking in a bit.

The Duke refused an offer to get some practice in by holding Corp Boggi’s two-year-old son Jenson, hastily saying: “No, no, you’re very kind.”

William received words of advice from other parents at the centre in Tidworth, Wiltshire,

He joked: “All the mothers have been looking at me, ‘just you wait, just you wait. Long sleepless nights’.”

RAF search and rescue pilot William and Harry, who completed his second tour of Afghanistan earlier this year, listened with interest as injured troops and their families explained how the centre has changed their lives.

During their tour, the princes had time to try their hand at some of the activities on offer.

Fresh from his recent tour in the US, Harry’s aim seemed well off the mark as he missed the basket seven times while playing netball.

He also caught up with members of the Warrior Games squad, who won 20 medals in this year’s tournament.

Harry was later invited to wave the flag to launch the 2013 Hero Ride, which will see more than 100 wounded troops cycle from all over the country to London.

William was handed personalised Help for Heroes hooded tops for himself and the Duchess of Cambridge before officially opening the centre.

He told guests: “This place - and what Help for Heroes and its partners have done here - makes Harry and me very, very proud.

“When Harry and I, like so many other young men and women, first donned our Help for Heroes wristbands only six years ago, not even we, as servicemen, could have guessed the scale of the challenges ahead.

“In 2007, the Nation was beginning to wake up to the reality of the debt that it owed its wounded and sick servicemen returning from Iraq and Afghanistan.

“The British public’s unprecedented response to the likes of Help for Heroes, the Royal British Legion and countless other service charities was a heartfelt response to that sense of debt felt by countless tens of thousands of people - in fact, the whole Nation - who wanted to show support and gratitude.

“Through the partnership between many service charities and the Ministry of Defence, it was the Nation who created this state-of-the-art Recovery Centre at Tedworth House and it falls to the Nation - to all of us - to continue to sustain it.”

Tedworth House is one of four centres run by Help for Heroes supporting 400 veteran and serving personnel at a cost of £7.5million a year.